Thanks again for posting this procedure again, Jerry
I read it with great interest. I have a spare "matched pair" 1954 3100 Hydra-Matic engine/transmission. If my working/running/rebuilt pair give-out, I like the odds of being able to use the engine-block which has this type of crack in it. It was originally spec'd for 4 PSI thermostat.
What is the chance that the crack is from freezing-expansion due to inadequate anti-freeze?
